lingo 循环语句中能不能使用if语句?
程序是这样的：
model:
3个化肥厂4个需求地运输问题;
sets:
huafeichang/1..3/:chanliang,youhui;
diqu/1..4/:xuqiu;
links(huafeichang,diqu):yunfei,yunliang,danjia;
endsets
目标函数;
min=@sum(links:dazhe*yunliang*danjia);
需求约束;
@for(diqu(J):
@sum(huafeichang(I):yunliang(I,J))=xuqiu(J));
产量约束;
@for(huafeichang(I):
@sum(diqu(J):yunliang(I,J))